xref: /linux-6.15/include/linux/can/dev.h (revision 32ae976e)
1 /*
2  * linux/can/dev.h
3  *
4  * Definitions for the CAN network device driver interface
5  *
6  * Copyright (C) 2006 Andrey Volkov <[email protected]>
7  *               Varma Electronics Oy
8  *
9  * Copyright (C) 2008 Wolfgang Grandegger <[email protected]>
10  *
11  */
12 
13 #ifndef _CAN_DEV_H
14 #define _CAN_DEV_H
15 
16 #include <linux/can.h>
17 #include <linux/can/netlink.h>
18 #include <linux/can/error.h>
19 #include <linux/can/led.h>
20 
21 /*
22  * CAN mode
23  */
24 enum can_mode {
25 	CAN_MODE_STOP = 0,
26 	CAN_MODE_START,
27 	CAN_MODE_SLEEP
28 };
29 
30 /*
31  * CAN common private data
32  */
33 struct can_priv {
34 	struct can_device_stats can_stats;
35 
36 	struct can_bittiming bittiming, data_bittiming;
37 	const struct can_bittiming_const *bittiming_const,
38 		*data_bittiming_const;
39 	struct can_clock clock;
40 
41 	enum can_state state;
42 	u32 ctrlmode;
43 	u32 ctrlmode_supported;
44 
45 	int restart_ms;
46 	struct timer_list restart_timer;
47 
48 	int (*do_set_bittiming)(struct net_device *dev);
49 	int (*do_set_data_bittiming)(struct net_device *dev);
50 	int (*do_set_mode)(struct net_device *dev, enum can_mode mode);
51 	int (*do_get_state)(const struct net_device *dev,
52 			    enum can_state *state);
53 	int (*do_get_berr_counter)(const struct net_device *dev,
54 				   struct can_berr_counter *bec);
55 
56 	unsigned int echo_skb_max;
57 	struct sk_buff **echo_skb;
58 
59 #ifdef CONFIG_CAN_LEDS
60 	struct led_trigger *tx_led_trig;
61 	char tx_led_trig_name[CAN_LED_NAME_SZ];
62 	struct led_trigger *rx_led_trig;
63 	char rx_led_trig_name[CAN_LED_NAME_SZ];
64 	struct led_trigger *rxtx_led_trig;
65 	char rxtx_led_trig_name[CAN_LED_NAME_SZ];
66 #endif
67 };
68 
69 /*
70  * get_can_dlc(value) - helper macro to cast a given data length code (dlc)
71  * to __u8 and ensure the dlc value to be max. 8 bytes.
72  *
73  * To be used in the CAN netdriver receive path to ensure conformance with
74  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
75  */
76 #define get_can_dlc(i)		(min_t(__u8, (i), CAN_MAX_DLC))
77 #define get_canfd_dlc(i)	(min_t(__u8, (i), CANFD_MAX_DLC))
78 
79 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
80 static inline int can_dropped_invalid_skb(struct net_device *dev,
81 					  struct sk_buff *skb)
82 {
83 	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
84 
85 	if (skb->protocol == htons(ETH_P_CAN)) {
86 		if (unlikely(skb->len != CAN_MTU ||
87 			     cfd->len > CAN_MAX_DLEN))
88 			goto inval_skb;
89 	} else if (skb->protocol == htons(ETH_P_CANFD)) {
90 		if (unlikely(skb->len != CANFD_MTU ||
91 			     cfd->len > CANFD_MAX_DLEN))
92 			goto inval_skb;
93 	} else
94 		goto inval_skb;
95 
96 	return 0;
97 
98 inval_skb:
99 	kfree_skb(skb);
100 	dev->stats.tx_dropped++;
101 	return 1;
102 }
103 
104 static inline bool can_is_canfd_skb(const struct sk_buff *skb)
105 {
106 	/* the CAN specific type of skb is identified by its data length */
107 	return skb->len == CANFD_MTU;
108 }
109 
110 /* get data length from can_dlc with sanitized can_dlc */
111 u8 can_dlc2len(u8 can_dlc);
112 
113 /* map the sanitized data length to an appropriate data length code */
114 u8 can_len2dlc(u8 len);
115 
116 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
117 void free_candev(struct net_device *dev);
118 
119 /* a candev safe wrapper around netdev_priv */
120 struct can_priv *safe_candev_priv(struct net_device *dev);
121 
122 int open_candev(struct net_device *dev);
123 void close_candev(struct net_device *dev);
124 int can_change_mtu(struct net_device *dev, int new_mtu);
125 
126 int register_candev(struct net_device *dev);
127 void unregister_candev(struct net_device *dev);
128 
129 int can_restart_now(struct net_device *dev);
130 void can_bus_off(struct net_device *dev);
131 
132 void can_change_state(struct net_device *dev, struct can_frame *cf,
133 		      enum can_state tx_state, enum can_state rx_state);
134 
135 void can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
136 		      unsigned int idx);
137 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
138 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
139 
140 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
141 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
142 				struct canfd_frame **cfd);
143 struct sk_buff *alloc_can_err_skb(struct net_device *dev,
144 				  struct can_frame **cf);
145 
146 #endif /* !_CAN_DEV_H */
147